Common use of Technical Approach Clause in Contracts

Technical Approach. Engineering of plants to be more nitrogen efficient would both increase ▇▇▇▇▇▇’▇ productivity and decrease the environmental impact of nitrogen applications. The Nitrogen Use Efficiency (NUE) technology developed at Arcadia is based on modulating the expression of an aminotransferase gene. While the GS/GOGAT cycle is the major route of nitrogen (N) assimilation in plants, altering the expression of enzymes directly involved in this cycle has not led to reproducible, field-demonstrated NUE. Aminotransferases are integral to N assimilation for the production of amino acids and N allocation in plants. Alanine aminotransferase enzymes catalyze the reversible formation of alanine and 2-oxoglutarate from glutamate and pyruvate. Increased NUE in transgenic plants expressing an alanine aminotransferase (AlaAT) from Hordeum vulgare under the control of a stress-inducible promoter from the Brassica napus turgor-responsive gene (btg26) was first demonstrated in canola (Good et al., 2007). Arcadia’s NUE technology enables plants to absorb and utilize nitrogen fertilizer much more efficiently than their non-transgenic controls. This results in the same high yields as conventional crops while using half as much nitrogen fertilizer, or higher yields if using the same amount of fertilizer. In either case, less nitrogen escapes into the water and air. Arcadia has granted licenses to multiple commercial seed companies for development and commercialization of this technology in crops, including: Monsanto (canola), DuPont/Pioneer (corn), ▇▇▇▇▇’▇ Company (turf), SES ▇▇▇▇▇▇▇▇▇▇ Seeds (sugar beets), Mahyco (multiple crops), and CSIRO/ACPFG (wheat and barley). Canola expressing btg-AlaAT has been extensively field tested for NUE by Arcadia since 2002. This work has progressed over 7 field seasons in the Imperial Valley of California and throughout the upper Midwestern United States. Typical results from application of urea fertilizer are shown in Figure 2A. Both the transgenic line and control plants respond to the application of N. Similar seed yields were achieved in the transgenic line using 66% less nitrogen than the control, Westar. In addition, seed yield was increased in the transgenic line by as much as 33% over the control at conventionally applied nitrogen levels. Figure 2. Seed yield of field grown NUE canola (A) and biomass accumulation (B). The transgenic plants accumulated significantly more biomass before bolting (Figure 2B) and the primary increase was in shoot biomass (data not shown). Extensive analyses on btg-AlaAT transgenic canola plants and seeds did not show any significant compositional differences at maturity. The plants showed no differences in nitrogen, phosphorus or potassium content. In addition, the seeds contained no differences in moisture content, size, protein content, amino acid composition, oil percentage or fatty acid composition. In addition to field studies, a greenhouse test system for biomass accumulation in the NUE transgenic plants has been established. The system is used to study the time course of biomass accumulation, the molecular and biochemical basis for the accumulation and for preliminary screening of new transgenic events. In addition to demonstrated field success in canola, Arcadia has promising NUE results in several varieties of japonica rice. In these experiments AlaAT is expressed under the control of the rice homologue of the btg related promoter OsAnt1. Both greenhouse and preliminary field trial results from Brawley, CA have shown increases in seed yield, panicle number and biomass in the transgenic lines as compared to controls under various nitrogen treatments. Figure 3A shows the grain yield differences of the transgenic lines (N4-13 and N4-15) as compared to the Nipponbare control under different applied nitrogen rates. Figure 3B shows that the increase seed yield is due to an increase in panicle number. These data are consistent with early generation data on these plants published recently by ▇▇▇▇▇▇▇ et al (2008).